The present invention relates to a method of and an arrangement for manufacturing enclosed blocks. More particularly, it relates to a method of and an arrangement for manufacturing blocks having a casing assembled from upper and lower parts, wherein the lower part is inserted into a mold chamber, the mold is filled with a filling material to be pressed, the upper part is applied, and the block is subjected to pressure between upper and lower pressing dies that engage the upper and lower parts of the block casing.
The thus manufactured refractory blocks, in which the filling material is predominantly a ceramic mass, are used for lining converters in which steel is melted from crude iron, such as Bessemer or Thomas converters. It has been recognized in the Steel industry that the casing of the individual blocks significantly increases the service life of the converter lining composed of these blocks. In accordance with a known method of manufacturing, a blockmaking press is utilized, for example as described in the German Offenlegungsschrift No. 2,741,800; it has vertical upper and lower pressing dies arranged opposite one another, and a mold table that is axially movable relative to the pressing die and supports a mold with a mold chamber through which the pressing dies can move. During a working stroke of the press, in which the mold chamber is closed from below by an upper surface of the lower pressing die, the lower part of the block casing is inserted by hand into the mold chamber, then a filling slider which is downwardly open and contains the filling material displaces during a further working stroke to a region above an upper surface of the mold so that the filling material falls into the mold chamber, and finally the upper part of the block casing is placed by hand onto the filling material and compressed by simultaneous raising of the mold table and the lower pressing die. In connection with this, either the filling material is first somewhat compressed in the mold before application of the upper part of the block casing and only after this the upper part is applied by hand, or the lower surface of the upper pressing die is provided with a holding template in which the upper part can be inserted in a position suitable for its treatment. The thus pressed block is then released by upwardly displacing the lower pressing die so that its pressing surface is flush with the upper surface of the mold, and then removed from the pressing surface by hand.
The above described method utilizes manual labor and therefore is time-consuming and expensive. Moreover, the insertion of the parts of the block casing by a worker requires his high concentration to prevent accidents. The known method is not suitable for manufacturing the blocks in great volumes required by wear-reducing properties of these blocks.